root

root

[roōt]

1. the descending and subterranean part of a plant.

2. that portion of an organ, such as a tooth, hair, or nail, that is buried in the tissues, or by which it arises from another structure, or the part of a nerve that is adjacent to the center to which it is connected.

Tooth anomalies with variations in root form. From Darby and Walsh, 1994.

anterior root the anterior, or motor, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the posterior root to form the nerve before it emerges from the intervertebral foramen; it conveys motor fibers to skeletal muscle and contains preganglionic autonomic fibers at the thoracolumbar and sacral levels. Called also ventral root.

nerve r's the series of paired bundles of nerve fibers which emerge at each side of the spinal cord, termed dorsal (or posterior) or ventral (or anterior) according to their position. There are 31 pairs (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal), each corresponding dorsal and ventral root joining to form a spinal nerve. Certain cranial nerves, e.g., the trigeminal, also have nerve roots.

posterior root the posterior, or sensory, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the anterior root to form the nerve before it emerges from the intervertebral foramen; each posterior root bears a spinal ganglion that conveys sensory fibers to the spinal cord. Called also dorsal root.

root

3. The descending underground portion of a plant; it absorbs water and nutrients, provides support, and stores nutrients.

4. Loosely used to denote the etiology of a process, event, or conflict requiring solutions to allow mitigation. For roots of pharmacologic significance that are not listed below, see specific names.

[A.S. rot]

root

(rldbomact) that portion of an organ, such as a tooth, hair, or nail, that is buried in the tissues, or by which it arises from another structure.

anterior root of spinal nerve the anterior, or motor, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the posterior root to form the nerve before it emerges from the intervertebral foramen.

Diagram of a horizontal section of the spinal cord, with posterior and anterior roots and a spinal nerve.

nerve roots the series of paired bundles of nerve fibers that emerge at each side of the spinal cord, termed posterior (or dorsal) or anterior (or ventral) according to their position. There are 31 pairs (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal), each corresponding posterior and anterior root joining to form a spinal nerve. Certain cranial nerves, e.g., the trigeminal, also have nerve roots.

posterior root of spinal nerve the posterior, or sensory, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the anterior root to form the nerve before it emerges from the intervertebral foramen.

root

that part of a plant which (usually) grows below ground. The root provides anchorage for the aerial parts, absorbs water and mineral salts from the soil, conducts water and nutrients to other parts of the plant, and often stores food materials over winter. Root structure is variable among higher plants, but generally the root, unlike the young STEM, has a central core of conducting tissue (the STELE) which also serves as a strong structural element, assisting the root as it pushes downwards and resisting upward pressures from the aerial parts.

Roots can be classified into three main types: primary, secondary (see LATERAL ROOT), and ADVENTITIOUS (1). The primary root of ANGIOSPERMS develops from the radicle of the seedling. Later, secondary roots emerge from the top of the primary root and then further down. At the apex of the root is a protective ROOT CAP. The typical root structure of a DICOTYLEDON is shown in Fig. 271.

In MONOCOTYLEDONS the number of xylem ‘arms’ is usually much greater than in DICOTYLEDONS, 12 to 20 in monocotyledons, 2 to 5 in dicotyledons. Roots frequently undergo SECONDARY THICKENING in dicotyledons, but not in monocotyledons.

root

(rūt) [TA]

1. Primary or beginning portion of any part, as of a nerve at its origin from the brainstem or spinal cord.

3. Loosely used to denote the etiology of a process, event, or conflict requiring solutions to allow mitigation.

[A.S. rot]

root,

n1. the part of a human tooth covered by cementum. n2. a nerve root; the part of a nerve adjacent to the center with which it is connected; in spinal and cranial nerves the part of the nerve between the cells of origin or termination and the ganglion.

n the angle formed by the intersection of the tooth root and the long axes of the crown. Where roots are sufficiently angulated, adequate bone formation occurs between the adjacent roots, which is important if the patient is particularly susceptible to periodontal bone loss.

root apex,

n the root tip.

root, apical

n the most inferior part or tip of the root of a tooth.

root axis line (RAL),

n a hypothetical vertical line that could be drawn from the crown of a tooth to the root apex.

root, bifurcated,

n the root structure of a tooth divided into two segments.

root canal,

n1. the soft, hollow, canal-like tissues of a tooth that adjoin the pulp chamber. The root canals help secure the teeth in the jaw, provide nutrition to the teeth through their blood vessels, and help sense oral cavity activity through their nerves. Infected root canals can be extremely painful. 2. the informal term for the endodontic procedure to remove infected root canal tissue and replace removed tissue with restorative material.

root canal, accessory,

n a nonprimary passage typically located near the root's apex that extends from the cementum to the pulp. It may be located at a higher point on the tooth and connect to a periodontal pocket.

root canal instrument stop,

n a device placed on a root canal instrument to mark the measured depth of instrument penetration.

root, clinical,

n the portion of the tooth that is below the attached periodontal tissues and not exposed to the oral cavity.

n the destruction of the cementum or dentin by cementoclastic or osteoclastic activity. It may result in a shortening or blunting of the root. Lateral root resorption may also occur, resulting in a loss of root substance along the side or length of the root. Severe lateral resorption may result in penetration of the pulp canal. Root resorption may be caused by inflammation resulting from trauma or infection, or it may be unknown or idiopathic. See also resorption.

Root resorption of the teeth.

root retention,

n removal of the crown of a root-canal treated tooth, whose periodontium is not adequate to support a prosthesis but with enough retention of the root and gingival attachment to support a removable prosthesis. See also overdenture.

root submersion,

n root retention in which the tooth structure is reduced below the level of the alveolar crest and the soft tissue is allowed to heal over it. It is believed that residual ridge resorption can be minimized by this approach. See also root retention.

root, trifurcated,

n the root structure of a tooth divided into three segments.

root trunk,

n the section of root nearest the crown from which multiple roots emerge.

root

1. the descending and subterranean part of a plant.

2. that portion of an organ, such as a tooth, hair or nail, that is buried in the tissues, or by which it arises from another structure, or the part of a nerve that is adjacent to the center to which it is connected, e.g. root of neck, root of tail.

calcified root canal

restriction of the diameter of the root canal due to calicification; seen in older animals.

root canal

that part of the dental pulp cavity extending from the pulp chamber to the apical foramen. Called also pulp canal.

screwdriver-shaped instrument with a grooved and beveled blade. By pushing the tip of the blade between the tooth root and the alveolar wall the periodontal membrane is broken and the root is elevated and removed.

dorsal root

the sensory division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the ventral root to form the nerve before it emerges from the intervertebral foramen.

hair root

the part of the hair buried in the hair follicle.

mesenteric root

the small area of attachment of the mesentery to the dorsal abdominal wall at about the level of the first lumbar vertebrae. It encloses the vessels and nerves that supply the intestine.

motor root

ventral root.

nerve r's

the series of paired bundles of nerve fibers which emerge at each side of the spinal cord, termed dorsal (or posterior) or ventral (or anterior) according to their position. A series of dorsal and ventral roots join to form a spinal nerve. Certain cranial nerves, e.g. the trigeminal, also have nerve roots.

penis root

the attachment of the penis by two crura to the lateral parts of the ischial arch.

referred pain down a limb, causing lameness or elevation of the limb, resulting from entrapment of the spinal nerve, usually by an extruded intervertebral disk.

root sheath cuticle

single layer of cornified cells of the hair follicle interdigitating with the cornified cells of the hair cuticle.

tongue root

caudal part of the tongue attached to the hyoid bone, soft palate and pharynx.

ventral root

the motor division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the dorsal root to form the nerve before it emerges from the intervertebral foramen.

Patient discussion about root

Q. How much does a root canal hurt? I have to get a root canal for my bottom tooth. I was wondering how much they hurt. And do you have any suggestions that help distract from the pain? Thanks.

A. i did one about two years ago- even the injection wasn't too bad! didn't feel a thing. but after the anesthesia worn off it hurt. but then the dentist told me to take Advil or any other NSAID and it helped.

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